(Invited) Electric-Field Driven Selective Electrocatalytic CO2 Conversion

Abstract

The efficient electrochemical conversion of CO2 to fuels or stock chemicals with high-energy density would be a major step forward in the introduction of a carbon neutral energy cycle. Especially, understanding the role of electrocatalysts, supports, and electrolytes that can efficiently reduce CO2 to fuels with high selectivity is a subject of significant interest.One of the achievements in electrochemical CO2 reduction is the clarification of the catalysts toward two-electron involved products such as CO and formate. For instance, CO is selectively generated on Au, Ag, and single-atom catalysts and formate has been selective on Hg, Pb, Sn or alloy catalysts. Interestingly, from our recent work, CO/formate ratio can be selectively controlled on formate selective catalyst by tuning the interfacial electric field.[1] On copper catalyst, the selection of alkali cations has direct influence on activity and product selectivity; increasing the size of mono-valent cations can increase the activity and selectivity toward C-C coupled products by modulating the interaction energy between adsorbates and electric fields at the interface.[2] In addition, copper catalyst with a specific atomic-scale gap accelerates the reaction kinetics and selectivity to C2+ products.[3] Therefore, understanding the roles of catalyst, support and electrolyte offers the design of efficient, yet cheap electrochemical CO2 reduction systems.[1] Y. Kwon et al., ACS Sustain. Chem. Eng. 2020, 8, 2117.[2] Y. Kwon et al., J. Am. Chem. Soc. 2016, 138, 13006.[3] Y. Kwon et al., Adv. Energy Mater. 2020, 1903423.